The detection of drugs of abuse in biological matrices using enzyme-linked immunosorbent assay and liquid chromatography-tandem mass spectrometry

Miller, Eleanor Isabel (2007) The detection of drugs of abuse in biological matrices using enzyme-linked immunosorbent assay and liquid chromatography-tandem mass spectrometry. PhD thesis, University of Glasgow.

Abstract

The aim of this study was to investigate the potential use of ELISA and LC-MS-MS in combination and as individual techniques, for the detection of drugs of abuse in biological matrices.

Overall the LC-MS-MS method showed good correlation results for opiates compared to the GC-MS method. 6-MAM was however detected in more root segments and segments excluding roots by LC-MS-MS. Morphine was detected in a greater number of root segments by LC-MS-MS compared to GC-MS. However, morphine was detected in a greater number of segments excluding roots by GC-MS. Codeine and dihydrocodeine were also detected in a greater number of root segments and segments excluding roots by GC-MS. The cocaine results showed excellent qualitative correlation between the LC-MS-MS and GC-MS methods for cocaine and benzoylecgonine. The GC-MS method did not however extract greater concentrations of cocaine and its metabolites compared to LC-MS-MS due to the higher recovery of the drug group specific GC-MS method. Cocaethylene and EME were detected in some samples by LC-MS-MS method for opiates and cocaine and its metabolites compared to the GC-MS method; there may be some cases where the GC-MS method would detect the analytes where the LC-MS-MS method would not. This has been demonstrated in 3 samples for morphine and in 6 samples for codeine.

The LC-MS-MS method analysed for and detected amphetamines in samples that were not tested for amphetamines by GC-MS. In one sample that was tested by both methods, amphetamine was detected in the root sample by LC-MS-MS where GC-MS failed to detect it. Also a greater concentration of amphetamine was extracted using the LC-MS-MS method in the segment without roots.

The LC-MS-MS method was useful for the analysis of 17 drugs of abuse in post-mortem hair samples in forensic toxicology cases. Using this method, it is possible to obtain maximum information from one hair sample which is extremely useful when the sample weight is limited. The ability of the LC-MS-MS method to extract and analyse a greater number of drug groups from one hair sample highlights the advantages of using this method over GC-MS which targets individual drug groups and requires splitting of the sample. This method is particularly applicable for implementation in the forensic toxicology laboratory at the University of Glasgow where currently GC-MS methods that target individual drug groups are used for routine hair screening and confirmation.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Subjects: Q Science > QH Natural history > QH301 Biology; R Medicine > RB Pathology; Q Science > QP Physiology
• Colleges/Schools: College of Medical Veterinary and Life Sciences > School of Cancer Sciences
• Supervisor's Name: Supervisor, not known
• Date of Award: 2007
• Depositing User: Elaine Ballantyne
• Unique ID: glathesis:2007-1516
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 17 Feb 2010
• Last Modified: 10 Dec 2012 13:41
• URI: https://theses.gla.ac.uk/id/eprint/1516